[PATCH] fix: net: ti: cpsw_init_common: fix excess of_node_put on parent node when cpts child not found

[PATCH] fix: net: ti: cpsw_init_common: fix excess of_node_put on parent node when cpts child not found

[WenTao Liang]

When no "cpts" child node exists in the device tree, cpts_node is
  assigned cpsw->dev->of_node without taking a reference via of_node_get.
  The function then unconditionally calls of_node_put(cpts_node) at the
  end, causing an excess put on the parent device node which can lead to a
  refcount underflow.

Use of_node_get when falling back to the parent node to ensure the
  reference count is properly balanced with the subsequent of_node_put.

Cc: stable@vger.kernel.org
Fixes: ed3525eda4c4 ("net: ethernet: ti: introduce cpsw switchdev based driver part 1 - dual-emac")
Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>
---
 drivers/net/ethernet/ti/cpsw_priv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/cpsw_priv.c b/drivers/net/ethernet/ti/cpsw_priv.c
index 1f6f374551cb..b20567f96d78 100644
--- a/drivers/net/ethernet/ti/cpsw_priv.c
+++ b/drivers/net/ethernet/ti/cpsw_priv.c
@@ -553,7 +553,7 @@ int cpsw_init_common(struct cpsw_common *cpsw, void __iomem *ss_regs,
 
 	cpts_node = of_get_child_by_name(cpsw->dev->of_node, "cpts");
 	if (!cpts_node)
-		cpts_node = cpsw->dev->of_node;
+		cpts_node = of_node_get(cpsw->dev->of_node);
 
 	cpsw->cpts = cpts_create(cpsw->dev, cpts_regs, cpts_node,
 				 CPTS_N_ETX_TS);
-- 
2.39.5 (Apple Git-154)

Re: [PATCH] fix: net: ti: cpsw_init_common: fix excess of_node_put on parent node when cpts child not found

[Andrew Lunn]

On Fri, Jun 26, 2026 at 11:29:45PM +0800, WenTao Liang wrote:
> When no "cpts" child node exists in the device tree, cpts_node is
>   assigned cpsw->dev->of_node without taking a reference via of_node_get.
>   The function then unconditionally calls of_node_put(cpts_node) at the
>   end, causing an excess put on the parent device node which can lead to a
>   refcount underflow.
> 
> Use of_node_get when falling back to the parent node to ensure the
>   reference count is properly balanced with the subsequent of_node_put.
> 
> Cc: stable@vger.kernel.org
> Fixes: ed3525eda4c4 ("net: ethernet: ti: introduce cpsw switchdev based driver part 1 - dual-emac")
> Signed-off-by: WenTao Liang <vulab@iscas.ac.cn>


    Andrew

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pw-bot: cr